Answer:
1.
2. If you ever wonder why nails rust, it's because rusting happens when a metal is exposed to oxygen.
3.The "rust" is actually iron oxide and forms when the iron in the nail reacts with the oxygen in the air or in liquids. The molecules of iron on the surface of the nail exchange atoms with the oxygen in the air and produce a new substance, the reddish-brown ferrous oxide, a.k.a. rust.
